Operator&#39;s cab for a work machine

ABSTRACT

An operator&#39;s cab for a work machine includes a ceiling structure and a floor structure. An operator&#39;s station is disposed between the ceiling structure and the floor structure, and is configured to position an operator in a driving position. First and second vertical support bars extend from the ceiling structure to the floor structure. The first and second vertical support bars are disposed forwardly of the operator&#39;s station land are spaced a substantially equal distance from a longitudinal axis of the work machine. Third and fourth vertical support bars also extend from the ceiling structure to the floor structure. The third and fourth vertical support bars are spaced a substantially equal distance from the longitudinal axis. The distance from the first and second vertical support bars to the longitudinal axis is less than the distance from the third and fourth vertical support bars to the longitudinal axis.

This application claims priority to U.S. Provisional application60/581,370, filed Jun. 22, 2004, which is incorporated herein byreference.

TECHNICAL FIELD

This disclosure is directed to an operator's cab and, more particularly,to an operator's cab for a work machine such as, for example, a motorgrader.

BACKGROUND

An operator's cab for a motor grader typically includes a number ofcontrols for operating the working tools on the motor grader. Forexample, one known motor grader uses sixteen different control levers tooperate the motor grader work tool. The controls extend across the frontof the operator's cab for easy access by the operator. Because so manycontrols are placed in front of the operator, operating cabs aretypically of a generally square configuration. Because the operator sitsbehind the controls, he may not have a view of the work tool and/or thefront wheels of the motor grader. Accordingly, during use, to get aproper view of the work tool, an operator may be required to stand orotherwise move within the operator's cab to a position where he hasincreased visibility.

In addition to providing a housing for the controls of the motor grader,an operator's cab should also be structurally sound. For example, theoperator's cab must be designed to protect an operator in the event of aroll-over. A support structure capable of withstanding such loads mayinclude vertical support bars extending from the top to the bottom ofthe operator's compartment. Because operator's cabs are typicallysquare, the vertical support bars may be placed at the corners. Verticalsupport bars at these locations are typically in the line of sight of anoperator and located directly between the operator and the work tool,such as the blade. Thus, the operator's view of the work tool may beimpaired. Improvements in the visibility of an operator may increaseefficiency and productivity of the operator running the motor grader.Increases in efficiency and productivity reduce costs.

U.S. Pat. No. 3,866,969 to Sandrock et al. discloses an operator's cabon a rubber tire front end loader. The operator's cab includes a frontwindshield that appears to be angled to the center of the cab from aside of the cab. However, the operator's compartment disclosed in the'969 patent does not increase the viewing area sufficient for a motorgrader. In addition, the location of the vertical support bars stillwould obstruct an operator's view when such an operator's compartmentwould be used on a motor grader. Accordingly, the operator's compartmentin the '969 patent does not disclose a system that would sufficientlyincrease visibility of an operator to the work tools of the motorgrader.

The disclosed operator's cab overcomes one or more of the deficienciesof the prior art by increasing an operator's viewing area.

SUMMARY OF THE INVENTION

In one aspect, this disclosure is directed to an operator's cab for awork machine. The operator's cab includes a ceiling structure and afloor structure. An operator's station is disposed between the ceilingstructure and the floor structure, and is configured to position anoperator in a driving position. First and second vertical support barsextend from the ceiling structure to the floor structure. The first andsecond vertical support bars are disposed forwardly of the operator'sstation and are spaced a substantially equal distance from alongitudinal axis of the work machine. Third and fourth vertical supportbars also extend from the ceiling structure to the floor structure. Thethird and fourth vertical support bars are spaced a substantially equaldistance from the longitudinal axis. The distance from the first andsecond vertical support bars to the longitudinal axis is less than thedistance from the third and fourth vertical support bars to thelongitudinal axis.

In another aspect, an operator's cab for a work machine is disclosed.The operator's cab includes a ceiling structure and a floor structure. Afirst and a second vertical support bar extend between the ceilingstructure and the floor structure. An operator's station in theoperator's cab is configured to position an operator in a drivingposition. A central region of the operator's station defines an indexaxis extending substantially perpendicular to an area of the operator'sstation. A first index angle is defined between a longitudinal axis ofthe work machine and a line extending from the index axis to the firstvertical support bar. Likewise, a second index angle is defined betweenthe longitudinal axis and a line extending from the index axis to thesecond vertical support bar. The first vertical support bar is disposedsuch that the first index angle is less than about 30 degrees and thesecond vertical support bar is disposed such that the second index angleis greater than about 70 degrees. The difference between the first indexangle and the second index angle defines a viewing angle that isunobstructed by a vertical support bar.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial representation of a side view of an exemplarymotor grader.

FIG. 2 is a pictorial representation of a top view of the exemplarymotor grader of FIG. 1.

FIG. 3 is a pictorial representation of an exemplary operator's cab fora motor grader.

FIG. 4 is an exemplary support structure used in the operator's cab ofFIG. 3.

FIG. 5 is a pictorial representation of a top view of the operator's cabof FIG. 3.

FIG. 6 is a pictorial representation of the cross-section of anexemplary vertical support bar.

FIG. 7 is a pictorial representation of an operator's view from theoperator's cab of FIG. 3.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments that areillustrated in the accompanying drawings. Wherever possible, the samereference numbers will be used throughout the drawings to refer to thesame or like parts.

An exemplary embodiment of a motor grader 100 is illustrated in FIGS. 1and 2. The motor grader 100 includes a rear frame section 102 and afront frame section 104. The rear frame section 102 includes a rearframe 106 and an engine in an engine compartment 108. The engine in theengine compartment 108 is mounted on the rear frame 106 and drives orpowers rear wheels 110 on the motor grader 100. While this particularembodiment is a motor grader, it is understood that the disclosedoperator's cab may have applications in other work machines.

The front frame section 104 includes a front frame 112, a blade assembly114, and an operator cab 116. The front frame 112 extends from frontwheels 118 to the rear wheels 110 and supports the operator cab 116. Theoperator cab 116 contains the many controls necessary to operate themotor grader 100.

The blade assembly 114 includes a blade 120 and a linkage assembly 122that allows the blade 120 to be moved to a variety of differentpositions relative to the motor grader 100. The linkage assembly 122includes a drawbar 124, a right lift cylinder 126, a left lift cylinder128 (FIG. 2), a center shift cylinder 130, and a coupling 132.

The drawbar 124 is mounted to the front frame 112, and its position iscontrolled by the right lift cylinder 126, the left lift cylinder 128,and the center shift cylinder 130. The coupling 128 connects the threecylinders 126, 128, and 130 to the front frame 112. The coupling 128 canbe moved during blade repositioning, but is fixed stationary duringearthmoving operations. The height of the blade 120 is controlledprimarily with the right and left lift cylinders 126, 128. The right andleft lift cylinders 126, 128 may be controlled independently and, thus,may be used to angle the blade 120 relative to the ground. The centershift cylinder 130 is used primarily to sideshift the drawbar 124, andall the components mounted to the end of the drawbar 124, relative tothe front frame 112.

The drawbar 124 includes a large, flat plate, commonly referred to as ayoke plate 134, as shown in FIG. 2. Beneath the yoke plate 134 is alarge gear or circle 136 (FIG. 1). The circle 136 may be rotated usingmethods known in the art to pivot the blade 120 about a blade axis 137to establish a blade cutting angle. The motor grader 100 includes alongitudinal axis 138 that defines a centerline of the motor grader inthis exemplary embodiment.

FIG. 3 is an isometric view of the operator's cab 116 separate from themotor grader 100. The operator's cab 116 includes a ceiling structure142, a floor structure 144, a front wall 146, and a back wall 148. Inaddition, the operator's cab 116 includes sidewalls 150 and obliquewalls 152. The front wall 146 includes a front window 154 and a frontpanel 156. The front panel 156 may connect directly to the front frame112 (shown in FIGS. 1 and 2) of the motor grader 100. The back wall 148includes a back window 158 and a back panel 160. The back panel 160 mayconnect directly to the rear frame 106 (shown in FIGS. 1 and 2) of themotor grader 100.

The side walls 150 and the oblique walls 152 connect the front and backwalls 146, 148. The side walls 150 are generally perpendicular to thefront and back walls 146, 148, while, as shown in FIG. 3, the obliquewalls 152 angle from the side walls 150 toward the front wall 146.Although the side and oblique walls 150, 152 are described as walls, itshould be apparent that they could be openings or could be formed of atransparent material such as glass or plastic. Accordingly, an operatorin the operator's cab 116 may be capable of looking through the side andoblique walls 150, 152. It should be noted that in one exemplaryembodiment, portions of the side and oblique walls 150, 152 may not betransparent. In one exemplary embodiment, the oblique walls 152 may forman entry or doorway into the operator's cab 116. The door may also beformed substantially of a transparent material, such as a glass orplastic. In another exemplary embodiment, the oblique walls 152 mayinclude a horizontal bar extending cross-wise to provide support.

Two entry handles 162 are shown on the exemplary operator's cab 116. Theentry handles 162 may be bars or handles placed for the convenience ofthe operator, and may be used when entering the cab, or climbing aladder into the cab. Within the operator's cab 116, a chair defining anoperator's station 164 may be disposed. The chair includes a front edge166 and positions the operator in a driving position.

FIG. 4 shows a support structure 170 of the operator's cab 116. Thesupport structure 170 may be capable of withstanding the weight of themotor grader 100, thereby protecting an operator in the event of arollover. The support structure 170 includes vertical support barsextending from the floor structure to the ceiling structure, such asfront vertical support bars 172, back corner vertical support bars 174,and side vertical support bars 176. The area between the front verticalsupport bars 172 and the side support bars 176 form the oblique wall 152of FIG. 3. The area between the back corner vertical support bars 174defines the back wall 148 of FIG. 3. Likewise, the area between the sidesupport bars 176 and the back corner vertical support bars 174 definesthe side walls 150 of FIG. 3. In the exemplary embodiment shown, each ofthe vertical support bars is disposed at an angle such that the supportbars are closer together at the floor structure 144 than at the ceilingstructure 142. Thus, each of the vertical support bars 172, 174, 176 maylean outwardly and away from the operator's station 164, such that a topportion of the vertical support bars is positioned farther away from theoperator's station than a bottom portion of the vertical support bars.Because of this, the front window 154 also leans outwardly and away fromthe operator's station 164. In one exemplary embodiment, only the frontvertical support bars 172 lean outwardly, while in another embodiment,the front and side vertical support bars 172, 176 lean outwardly.However, the vertical support bars could be substantially vertical ortaper inwardly in other exemplary embodiments.

In one exemplary embodiment, horizontal support bars may extend betweentwo or more of the vertical support bars 172, 174, 176. Otherconfigurations may be used as would be apparent to one skilled in theart. For example, in this exemplary embodiment, the operator's cab 116includes two front vertical support bars 172. However, it should beapparent to one skilled in the art that one vertical support bar couldbe provided.

FIG. 5 shows the top view of the operator's cab 116 with the ceilingstructure removed. In this exemplary embodiment, the front verticalsupport bars 172 are substantially equally spaced from the longitudinalaxis 138. Likewise, the side and rear vertical support bars 174, 176 aresubstantially equally spaced from the longitudinal axis 138. In thisexemplary embodiment, the distance from the front vertical support bars172 to the longitudinal axis 138 is less than the distance from the sideand rear vertical support bars 174, 176 to the longitudinal axis. Thisenables the floor structure 144 to be beveled, as shown by beveled edges178 extending from the side walls to the front wall. In one exemplaryembodiment, the beveled edge 178 is angled within a range of 20-50degrees. In one exemplary embodiment, the angle is at around 30 degrees.However, other angles could be used.

In this particular disclosed embodiment, the side and rear verticalsupport bars 174, 176 form a generally rectangular shape containingsubstantially all of the operator station 164. As can be seen, the sidevertical support bars 176 are disposed adjacent to the operator'sstation 164. They may also be disposed rearward of the front edge 166 ofthe operator's station 164.

The operator's station 164 includes an index axis 180, which representsthe general position of an operator's eyes, with varying height, whenthe operator is appropriately seated in the operator's station 164. Theindex axis 180 may be defined at the operator's station 164 as being asubstantially vertical axis (with reference to the base of theoperator's seat) extending upward from the central area of an operatorseat. It is anticipated that the eyes of an operator in the operator'sstation 164 may be within a range of about 1.5 to 3.5 feet above theseat of the operator's station, and generally along the index axis 180.

The visibility of an operator will be described with reference to anindex angle θ and a viewing angle Ψ. As set forth more clearly below,the index angle θ is the angle formed between the longitudinal axis 138and a line drawn between the index axis 180 and a vertical support bar.The viewing angle Ψ corresponds to the view of an operator betweenadjacent vertical support bars. As shown in FIG. 5, the front verticalsupport bars 172 may be disposed at an index angle θ₁, such as forexample, 10 degrees. The next adjacent vertical support bar is disposedat an index angle θ₂, which could be, for example, 80 degrees. Bycalculating the difference between the two index angles, the viewingangle Ψ, corresponding to the angle unobstructed by vertical supportbars relative to an operator, may be determined. In the example shown inFIG. 5, the viewing angle Ψ may be calculated to be 70 degrees. Itshould be noted that other angles may be used. In one exemplaryembodiment, the index angle θ₁ is less than 30 degrees, and the indexangle θ₂ is greater than 70 degrees. Thus, the viewing angle Ψ isgreater than 40 degrees. In another exemplary embodiment, the indexangle θ₁ is less than 20 degrees, and the index angle θ₂ is greater than70 degrees. Thus, the viewing angle Ψ is greater than 50 degrees. In yetanother exemplary embodiment, the index angle θ_(‘)is less than 15degrees, and the index angle θ₂ is greater than 70 degrees. Thus, theviewing angle Ψ is greater than 55 degrees.

In one exemplary embodiment, because the viewing angle Ψ is determinedin part by the location of the oblique wall 152, which may be a door orentry to the operator's cab 116, the viewing angle Ψ may include ahorizontal support bar and/or a door handle. However, the viewing angledoes not include a vertical support bar within that range. The index andviewing angles may change when the position of the seat or operator'sstation is changed relative to the vertical support bars.

FIG. 6 is a cross sectional view of an exemplary vertical support bar182 that may be used on the operator's cab 116. The vertical support bar182 is a trapezoid shape, including two substantially parallel surfaces184. In addition, the vertical support bar 182 includes tapered walls188 that are aligned with a line of sight 186 of an operator. Thisconfiguration enables the operator to have an enhanced viewing area,while still providing a sufficient support structure for the operatorcab. In one exemplary embodiment, the vertical support bar 182 has arectangular shape and i s disposed so that the narrow edge of therectangle is facing the operator's station.

INDUSTRIAL APPLICABILITY

The operator's cab 116 enhances the visibility of an operatorcontrolling a work machine, such as the motor grader 100. FIG. 7 showsan exemplary view of an operator from the index axis 180 in theoperator's cab 116. As shown in FIG. 7, an operator sitting in theoperator's station 164 may be able to view working tools of the motorgrader 100, such as, for example, the blade 120 and/or the front wheels118 of the motor grader 100, by looking out the front window 154 andthrough the transparent area defining the oblique walls 152. As shown inFIG. 7, edges at both ends of the blade 120 are visible. In a preferredembodiment, the operator's cab may be configured to provide no viewingimpairment to an operator's ability to view both ends of the blade 120throughout the blade's full range of rotation. The operator's cab may beconfigured to provide such a view to an operator in the operator'sstation 164, when the operator's eyes are disposed generally along theindex axis 180, and within the range of about 1.5 to 3.5 feet above theseat of the operator's station 164. In another exemplary embodiment, theoperator's cab may be configured to provide such a view when theoperator's eyes are disposed generally along the index axis 180, andwithin the range of about 2 to 3 feet above the seat of the operator'sstation 164.

Because an operator can more easily view the working components, theoperator may require less training and, in addition, work moreefficiently. This reduces training costs and increasing productivity.Further, the enhanced visibility afforded by the disclosed operator'scab may be obtained without creating safety concerns. The disclosedoperator's cab may be a robust design capable of protecting an operatorin the event of a rollover.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the disclosed embodimentswithout departing from the scope of the invention. Other embodiments ofthe invention will be apparent to those skilled in the art fromconsideration of the specification and practice of the inventiondisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the invention beingindicated by the following claims and their equivalents.

1. An operator's cab for a work machine, comprising: a ceilingstructure; a floor structure; an operator's station disposed between theceiling structure and the floor structure, and configured to position anoperator in a driving position; first and second vertical support barsextending from the ceiling structure to the floor structure, the firstand second vertical support bars being disposed forwardly of theoperator's station, and being spaced a substantially equal distance froma longitudinal axis of the work machine; and third and fourth verticalsupport bars extending from the ceiling structure to the floorstructure, the third and fourth vertical support bars being spaced asubstantially equal distance from the longitudinal axis, wherein thedistance from the first and second vertical support bars to thelongitudinal axis is less than the distance from the third and fourthvertical support bars to the longitudinal axis.
 2. The operator's cab ofclaim 1, wherein the operator's station is a seat.
 3. The operator's cabof claim 1, including fifth and sixth vertical support bars extendingfrom the ceiling structure to the floor structure, the fifth and sixthvertical support bars being disposed at a rear of the cab and beingspaced a substantially equal distance from the longitudinal axis,wherein the distance from the first and second vertical support bars tothe longitudinal axis is less than the distance from the fifth and sixthvertical support bars to the longitudinal axis.
 4. The operator's cab ofclaim 1, including fifth and sixth vertical support bars extending fromthe ceiling structure to the floor structure, the third, fourth, fifth,and sixth vertical support bars defining a substantially rectangularshape, the operator's station being substantially disposed within therectangular shape.
 5. The operator's cab of claim 1, including a doordisposed in at least one of a first area between the first and thirdsupport bars and a second area between the second and fourth verticalsupport bars.
 6. The operator's cab of claim 1, wherein the floorstructure is beveled to be more narrow between the first and secondvertical support bars than between the third and fourth vertical supportbars.
 7. The operator's cab of claim 1, wherein the first and secondvertical support bars are disposed at an incline such that a top portionof the first and second vertical support bars is positioned farther awayfrom the operator's station than a bottom portion of the verticalsupport bars.
 8. The operator's cab of claim 1, wherein an area betweenthe first and third support bars and an area between the second andfourth vertical support bars is unobstructed by any other support bar.9-23. (canceled)
 24. The operator's cab of claim 2, wherein the thirdand fourth vertical support bars are disposed adjacent a front of theseat on opposing sides of the seat.
 25. The operator's cab of claim 1,wherein one of the first and second vertical support bars and one of thethird and fourth vertical support bars form an oblique wall.
 26. Theoperator's cab of claim 25, wherein the oblique wall is made of atransparent material.
 27. An operator's cab for a work machine,comprising: a ceiling; a floor; an operator's station disposed betweenthe ceiling and the floor and configured to position an operator in adriving position; a front wall; a back wall; two side walls; and twooblique walls; wherein each of the oblique walls is connected to thefront wall and a side wall, and each side wall is connected to anoblique wall and the back wall.
 28. The operator's cab of claim 27,wherein the side walls are substantially perpendicular to both the frontwall and the back wall.
 29. The operator's cab of claim 27, wherein thefront wall includes a window.
 30. The operator's cab of claim 27,wherein the back wall includes a window.
 31. The operator's cab of claim27, wherein at least a portion of the side walls are made of atransparent material.
 32. The operator's cab of claim 27, wherein atleast a portion of the oblique walls are made of a transparent material.33. A motor grader, comprising: a front frame; a rear frame disposedadjacent the front frame; an operator's station disposed between aceiling structure and a floor structure, and configured to position anoperator in a driving position; first and second vertical support barsextending from the ceiling structure to the floor structure, the firstand second vertical support bars being disposed forwardly of theoperator's station, and being spaced a substantially equal distance froma longitudinal axis of the work machine; and third and fourth verticalsupport bars extending from the ceiling structure to the floorstructure, the third and fourth vertical support bars being spaced asubstantially equal distance from the longitudinal axis, wherein thedistance from the first and second vertical support bars to thelongitudinal axis is less than the distance from the third and fourthvertical support bars to the longitudinal axis.
 34. The motor grader ofclaim 33, including fifth and sixth vertical support bars extending fromthe ceiling structure to the floor structure, the fifth and sixthvertical support bars being disposed at a rear of the cab and beingspaced a substantially equal distance from the longitudinal axis,wherein the distance from the first and second vertical support bars tothe longitudinal axis is less than the distance from the fifth and sixthvertical support bars to the longitudinal axis.
 35. The motor grader ofclaim 33, including fifth and sixth vertical support bars extending fromthe ceiling structure to the floor structure, the third, fourth, fifth,and sixth vertical support bars defining a substantially rectangularshape, the operator's station being substantially disposed within therectangular shape.